
<span id="numpy-ma-constants"></span><h1><span class="yiyi-st" id="yiyi-33">Constants of the <code class="xref py py-mod docutils literal"><span class="pre">numpy.ma</span></code> module</span></h1>
        <blockquote>
        <p>原文：<a href="https://docs.scipy.org/doc/numpy/reference/maskedarray.baseclass.html">https://docs.scipy.org/doc/numpy/reference/maskedarray.baseclass.html</a></p>
        <p>译者：<a href="https://github.com/wizardforcel">飞龙</a> <a href="http://usyiyi.cn/">UsyiyiCN</a></p>
        <p>校对：（虚位以待）</p>
        </blockquote>
    
<p><span class="yiyi-st" id="yiyi-34">除了<a class="reference internal" href="#numpy.ma.MaskedArray" title="numpy.ma.MaskedArray"><code class="xref py py-class docutils literal"><span class="pre">MaskedArray</span></code></a>类，<code class="xref py py-mod docutils literal"><span class="pre">numpy.ma</span></code>模块定义了几个常量。</span></p>
<dl class="data">
<dt id="numpy.ma.masked"><span class="yiyi-st" id="yiyi-35"> <code class="descclassname">numpy.ma.</code><code class="descname">masked</code></span></dt>
<dd><p><span class="yiyi-st" id="yiyi-36"><a class="reference internal" href="#numpy.ma.masked" title="numpy.ma.masked"><code class="xref py py-attr docutils literal"><span class="pre">masked</span></code></a>常量是<a class="reference internal" href="#numpy.ma.MaskedArray" title="numpy.ma.MaskedArray"><code class="xref py py-class docutils literal"><span class="pre">MaskedArray</span></code></a>的特殊情况，具有float数据类型和null形状。</span><span class="yiyi-st" id="yiyi-37">它用于测试被屏蔽数组的特定条目是否被屏蔽，或者屏蔽被屏蔽数组的一个或多个条目：</span></p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">x</span> <span class="o">=</span> <span class="n">ma</span><span class="o">.</span><span class="n">array</span><span class="p">([</span><span class="mi">1</span><span class="p">,</span> <span class="mi">2</span><span class="p">,</span> <span class="mi">3</span><span class="p">],</span> <span class="n">mask</span><span class="o">=</span><span class="p">[</span><span class="mi">0</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">0</span><span class="p">])</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">x</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="ow">is</span> <span class="n">ma</span><span class="o">.</span><span class="n">masked</span>
<span class="go">True</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">x</span><span class="p">[</span><span class="o">-</span><span class="mi">1</span><span class="p">]</span> <span class="o">=</span> <span class="n">ma</span><span class="o">.</span><span class="n">masked</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">x</span>
<span class="go">masked_array(data = [1 -- --],</span>
<span class="go">             mask = [False  True  True],</span>
<span class="go">       fill_value = 999999)</span>
</pre></div>
</div>
</dd></dl>
<dl class="data">
<dt id="numpy.ma.nomask"><span class="yiyi-st" id="yiyi-38"> <code class="descclassname">numpy.ma.</code><code class="descname">nomask</code></span></dt>
<dd><p><span class="yiyi-st" id="yiyi-39">指示掩码数组没有无效条目的值。</span><span class="yiyi-st" id="yiyi-40"><a class="reference internal" href="#numpy.ma.nomask" title="numpy.ma.nomask"><code class="xref py py-attr docutils literal"><span class="pre">nomask</span></code></a>在内部用于在不需要掩码时加快计算速度。</span></p>
</dd></dl>
<dl class="data">
<dt id="numpy.ma.masked_print_options"><span class="yiyi-st" id="yiyi-41"> <code class="descclassname">numpy.ma.</code><code class="descname">masked_print_options</code></span></dt>
<dd><p><span class="yiyi-st" id="yiyi-42">打印掩码数组时用于替换缺少数据的字符串。</span><span class="yiyi-st" id="yiyi-43">默认情况下，此字符串为<code class="docutils literal"><span class="pre">&apos;--&apos;</span></code>。</span></p>
</dd></dl>
